Parameter Sensitivity of the Noah-MP Land Surface Model with Dynamic Vegetation

Abstract

The Noah land surface model with multiple parameterization options (Noah-MP) includes a routine for dynamic simulation of vegetation carbon assimilation and soil carbon decomposition processes. To use remote sensing observations of vegetation to constrain simulations from this model, it is necessary first to understand the sensitivity of the model to its parameters. This is required for efficient parameter estimation, which is both a valuable way to use observations and also a first or concurrent step in many state-updating data assimilation procedures. We use variance decomposition to assess the sensitivity of estimates of sensible heat, latent heat, soil moisture, and net ecosystem exchange made by certain standard Noah-MP configurations that include dynamic simulation of vegetation and carbon to forty-three primary user-specified parameters. This is done using thirty-two years' worth of data from ten international FluxNet sites. Findings indicate that there are five soil parameters and six (or more) vegetation parameters (depending on the model configuration) that act as primary controls on these states and fluxes